Multistable flexible inflatable ballistic blast shelter

Abstract

The present application provides a kind of multistable flexible inflatable bulletproof blast shelter, can be by elastic deformation to " capture " part of energy of input system, to cope with impact energy, satisfy " light portable, strong protection " blast protection structure's demand.The tent cloth of the bulletproof blast shelter is multilayer structure, at least has: bulletproof layer, energy absorption layer and air pillow buffer wave deformation layer;Above-mentioned each layer is using flexible material;Wherein the bulletproof layer is located outermost, the air pillow buffer wave deformation layer is located the inner side of the energy absorption layer;The air pillow buffer wave deformation layer is inflatable structure, including low pressure cell and high pressure cell;The high pressure cell and low pressure cell are sequentially spaced along height direction and form the air pillow buffer wave deformation layer with multistable structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a tent, in particular to a bulletproof and anti-explosion tent, and belongs to the technical field of public safety protection. BACKGROUND

[0002] The protective equipment of the border front line is insufficient in protective ability, and the conventional high-resistance protective equipment needs to be built by machinery. The border front line urgently needs to build protective equipment that is light and portable and has strong protection. The main factor restricting the protective performance of the project is the backwardness of the current military composite materials and structure. For example, the highland field fortification commonly used at present mostly uses canvas and other materials. Although it is lightweight and meets the requirements of human carrying, the structural strength cannot meet the needs of bulletproof and explosion-proof, which is not conducive to the timely deployment of confrontation and garrison in high-altitude areas. The mobile operation in the high-altitude and cold harsh environment has a major demand for the heat preservation and pressure preservation effect of the fortification. However, the current field fortification cannot well solve the problem of heat and pressure preservation, which greatly reduces the confrontation ability of long-term garrison. In addition, in order to protect conventional ammunition, the traditional protective fortification adopts a rigid plastic energy-absorbing mechanism, but its weight is large, which limits its mobility in the highland combat environment.

[0003] The protective camp is an important garrison place for troops in combat, used to protect the safety of combat personnel and equipment. Common protective equipment in China includes permanent structures, semi-permanent structures, and temporary structures. Generally, permanent structures are built with sand and stones according to local conditions, which have long construction periods, poor timeliness, waste combat power, and are not easy to move after completion, with low utilization rate. The combined structure (thin steel plate + rock wool / polyurethane / polyphenyl foam + thin steel plate) sandwich structure can be assembled into a semi-permanent structure. The composite structure has relatively light weight and can be modularized by large lifting machinery to form a scale. The temporary camp tent built with flexible double-layer PVC coated cloth and high-strength canvas can be quickly built by manpower. However, barracks in field operations are generally the main targets of attack, and when they encounter artillery attacks, they will suffer significant losses of personnel and equipment due to the lack of special protection. The conventional protective equipment has application bottlenecks in terms of protection performance and mobility. The modern field anti-explosion protection field urgently needs a comprehensive protective structure that is light, easy to deploy, resistant to explosions and certain fragment impacts. It has become an inevitable trend to develop protective structures that are light, portable, and have strong protection.

[0004] In the process of biological evolution, multi-phase structures that adapt to survival needs have gradually evolved, providing a reference for material selection and structure configuration. The Venus flytrap can make the leaves curl up and stretch by changing the pressure between cells. When stimulated by insects, the insect-catching clamp closes around its leaf veins. These leaves do not need complex driving and simply rely on intracellular pressure to drive, achieving high efficiency in leaf contraction and bending.

[0005] Multistable effects are a phenomenon that occurs during buckling step stresses. Multistable structures can rapidly transition between states and remain stable in different steady-state configurations under the influence of external threshold driving forces. They can "capture" part of the energy input to the system through multi-order elastic deformation to cope with impacts. Multistable structures are generally based on geometric and material nonlinearity, achieving bistable and even multistable mechanical properties through the overall beam configuration design and material distribution. Uniform shell structures only exhibit bistable characteristics, while multistable variant structures are constructed based on variable thickness plates, i.e., non-uniform stiffness. The rational arrangement of circumferential stiffeners allows the structure to possess multi-level steady-state characteristics such as bistable, tristable, and tetrastable, increasing the energy absorption rate. Multistable responses have the advantages of reusability and no secondary damage, which can be fully utilized in personnel protection and protective packaging of precision components. Summary of the Invention

[0006] In view of this, inspired by the various stable forms of the Venus flytrap, this invention provides a multi-stable flexible inflatable bulletproof and blast-resistant tent that can "capture" part of the energy input to the system through elastic deformation in order to cope with impact energy and meet the requirements of a "lightweight, portable, and highly protective" blast-resistant structure.

[0007] The technical solution of the present invention is: a multi-stable flexible inflatable bulletproof and explosion-proof tent, wherein the tent fabric has a multi-layer structure, including at least: a bulletproof layer, an energy-absorbing layer, and an air cushion buffering and deformation layer; each of the above layers is made of flexible material; wherein the bulletproof layer is located on the outermost side, and the air cushion buffering and deformation layer is located on the inner side of the energy-absorbing layer;

[0008] The air cushion buffer trimming deformation layer is an inflatable structure, including low-pressure cells and high-pressure cells; the high-pressure cells and low-pressure cells are arranged alternately along the height direction to form an air cushion buffer trimming deformation layer with a multi-stable structure.

[0009] In a preferred embodiment of the present invention, the arc-shaped cell at the top is a low-pressure cell.

[0010] In a preferred embodiment of the present invention, in the air cushion buffer trimming deformation layer, the air pressure in each low-pressure cell increases sequentially from top to bottom along the height direction, and the air pressure in each high-pressure cell increases sequentially from top to bottom along the height direction; and the air pressure in each high-pressure cell is greater than the air pressure in the two adjacent low-pressure cells.

[0011] As a preferred embodiment of the present invention, two or more of the aforementioned air cushion buffer trimming deformation layers are stacked; wherein the air pressure in each cell of the inner air cushion buffer trimming deformation layer is greater than the air pressure in the corresponding cells of the outer air cushion buffer trimming deformation layer.

[0012] In a preferred embodiment of the present invention, the air pressure in the high-pressure cell is greater than 15 MPa; and the air pressure in the low-pressure cell is greater than 10 MPa.

[0013] In a preferred embodiment of the present invention, the innermost layer of the bulletproof and explosion-proof tent fabric is an anti-dent layer.

[0014] In a preferred embodiment of the present invention, a flame-retardant layer is provided on the outer side of the energy-absorbing layer.

[0015] In a preferred embodiment of the present invention, the ballistic layer is a fiber ballistic layer; the energy-absorbing layer is made of porous polyurethane foam; and the air-cushion buffering and shaping deformation layer is made of polyurethane superelastic material.

[0016] In a preferred embodiment of the present invention, the flame-retardant layer is made of high-temperature resistant aramid fiber.

[0017] In a preferred embodiment of the present invention, each layer of the bulletproof and explosion-proof tarpaulin has a hemispherical structure, and the air cushion buffering and shaping layer includes five annular cells arranged sequentially along the height direction and an arc-shaped cell located at the top center.

[0018] Beneficial effects:

[0019] (1) The pillow buffer clipping deformation layer in the multistable flexible inflatable bulletproof and explosion-proof tent of the present invention is a multistable structure, which can "capture" part of the energy input to the system through elastic deformation to cope with the impact energy and meet the requirements of "lightweight and portable, strong protection" explosion-proof protection structure.

[0020] (2) In the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention, the tent fabric is a multi-layer structure. Considering that the tent is often in the far field of the multi-physics field of the explosion, the fragment load will be loaded onto the tent first under the explosion drive. Based on the loading sequence problem of fragments first and shock wave later, the bulletproof layer is set as the explosion-facing (bullet) surface. Thus, the large deformation and plastic strengthening of the bulletproof layer are used to weaken the fragments first. A flame-retardant layer is set on the front side of the energy-absorbing layer to avoid the generation of high-temperature fireballs under the explosion drive, which would cause the energy-absorbing layer to fail.

[0021] (3) In the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention, an anti-dent layer is provided on the innermost side, which can avoid injury to personnel due to large dents in the tent.

[0022] (4) In the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention, the low-pressure cell has better buffering and deformation performance, and the high-pressure cell has better support performance; the alternating arrangement of high and low pressure can balance the energy absorption buffering and anti-collapse performance of the tent.

[0023] (5) In the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention, the stacking of the air cushion buffer deformation layer can give full play to the energy absorption effect of the cell in the normal direction; at the same time, the stacking can effectively ensure the supporting role of the innermost air cushion buffer deformation layer and prevent the tent from collapsing prematurely.

[0024] (6) In the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention, the arc-shaped cell at the top is a low-pressure cell. Under the action of the explosion shock wave, the cell structure at the top will first be compressed and deformed by the shock wave, which can effectively weaken the peak value of the shock wave. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the composition of the multi-stable flexible inflatable bulletproof and explosion-proof tent fabric of the present invention and the mechanism of action of the explosion shock wave on the bulletproof and explosion-proof tent;

[0026] Figure 2 This is a schematic diagram of the protective mechanism of the multi-stable flexible inflatable bulletproof and explosion-proof tent of the present invention;

[0027] Among them: 1-ballistic layer, 2-flame retardant layer, 3-energy absorption layer, 4-air cushion buffer and deformation layer, 41-low pressure cell, 42-high pressure cell, 5-anti-dentation layer; 6-cased explosive charge. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0029] Inspired by the various stable forms of the Venus flytrap, this embodiment provides a multistable flexible inflatable bulletproof and blast-resistant tent. The tent has a multistable structure that mimics the form of cell molecules. It can "capture" part of the energy input to the system through elastic deformation to cope with impact energy and meet the needs of a new type of blast-resistant protective structure that is "lightweight, portable and highly protective".

[0030] like Figure 1 As shown, the tent fabric of this bulletproof and explosion-proof tent has a multi-layer structure, consisting of the following layers from the outside to the inside: bulletproof layer 1, flame-retardant layer 2, energy-absorbing layer 3, air cushion buffering and deformation layer 4, and anti-dent layer 5; all of the above layers are made of flexible materials.

[0031] The design mechanism of the above multi-layered structure is as follows: Considering that tents are often located in the far field of a multi-physics explosion, the fragment load will be applied to the tent first under the explosion-driven conditions. Based on the loading sequence problem of fragments first and shock wave later, the ballistic layer 1 is set as the blast (projectile) facing surface, thus first using the large deformation and plastic strengthening of the ballistic layer 1 to weaken the fragments. The energy-absorbing layer 3 is formed by polyurethane foam. Considering that polyurethane foam is flammable and a high-temperature fireball will be generated under the explosion-driven conditions, which may cause the polyurethane foam to fail, the flame-retardant layer 2 is set in front of the polyurethane energy-absorbing layer 3. The energy-absorbing layer 3 and the air cushion buffer and wave-shrinking deformation layer 4 play the role of weakening the peak value of the shock wave and absorbing the shock wave energy, and are placed in the third and fourth layers respectively. As a protective structure for personnel, the degree of structural indentation needs to be considered to prevent injury to personnel. Therefore, the anti-indentation layer 5 is set as the fifth layer, i.e., the innermost layer. This type of tent structure overcomes the shortcomings of existing protective tents in terms of insufficient protective and pressure-holding capabilities; combined with the protective concept of "using flexibility to overcome rigidity", it can give full play to the protective advantages of high energy absorption of flexible materials.

[0032] When a cased explosive charge is applied to this bulletproof and blast-resistant tent, the main lethal load of the blast wave is divided into overpressure P. i With fragment velocity V i When the shockwave from the explosion acts on the bulletproof and blast-resistant tent, it first passes through the bulletproof layer 1 and the flame-retardant layer 2. The impact velocity V of the fragments is greatly reduced through the film stretching effect of the high-performance fibers. i Through the shock wave reflection and transmission effect, the overpressure P i Only a slight reduction. When the blast shock wave acts on the third energy-absorbing layer 3, the load is mainly an overpressure load. Through the collapse energy absorption effect of the porous polyurethane foam, the shock wave energy is fully absorbed; the fourth air cushion buffer and clipping deformation layer 4 can further weaken the overpressure peak. After passing through the third and fourth layers, the shock wave load can be effectively protected. Figure 1 The arrows in the diagram indicate the overpressure P at the corresponding location. i With fragment velocity V i ).

[0033] Depending on the environment and type of damage load, different thickness ratios are set for the layers of the bulletproof and blast-resistant tent fabric. For example, when facing threats such as bullets that use projectiles as the killing mechanism, the thickness of the ballistic layer 1 can be increased, while the thicknesses of the energy-absorbing layer 3 and the air cushion trimming layer 4 can be further reduced. When facing a 12.7mm caliber projectile traveling at 400m / s, the thickness ratio of the ballistic layer 1, flame-retardant layer 2, energy-absorbing layer 3, air cushion trimming deformation layer 4, and anti-dentation layer 5 can be 10:5:1:100:5. When facing threats such as low-yield, cased explosive charges and grenades that use blast waves and fragments as the killing mechanism, due to the lower penetration capability of fragments, the thickness of the ballistic layer 1 can be appropriately reduced, and the thickness ratio of the ballistic layer 1, flame-retardant layer 2, energy-absorbing layer 3, air cushion trimming deformation layer 4, and anti-dentation layer 5 can be 2:2:3:100:2.

[0034] Based on the interlayer incident, reflection, and transmission of shock waves, as well as the attenuation law of fragment velocity, and the influence mechanism of multi-layered structures and multi-phase materials on various loads generated by an explosion, the tent's layers utilize flexible materials such as high-temperature resistant aramid fibers, ultra-high molecular weight polyethylene fibers, porous polyurethane foam, and polyurethane superelastic materials. As an example, the ballistic layer 1 is a fiber-reinforced ballistic layer, using ultra-high molecular weight polyethylene fibers, with a structure that can be unidirectional or orthogonal; the flame-retardant layer 2 uses high-temperature resistant aramid fibers, with a structure that can be two-dimensional woven fabric, three-dimensional woven fabric, or unidirectional fabric; the energy-absorbing layer 3 uses porous polyurethane foam; the air cushion buffer and trimming deformation layer 4 is an inflatable structure, with the inflatable membrane using polyurethane superelastic material; and the anti-dentation layer 5 uses ultra-high molecular weight polyethylene fibers, with a structure that can be unidirectional or orthogonal fabric.

[0035] like Figure 2 As shown, the air cushion buffer trimming deformation layer 4 establishes a multi-stable structure based on air cushion cells, enabling the bulletproof and blast-resistant tent to possess multi-stage stable states. Multi-stable structures are generally simpler in single-unit designs, but more complex multi-stable structures can be obtained through arrays. Therefore, in this embodiment, the air cushion buffer trimming deformation layer 4 is divided into multiple cells with different internal pressures along the height direction to form a multi-stable structure. As an example, each layer of the tent fabric is a hemispherical structure. Thus, the air cushion buffer trimming deformation layer 4 includes multiple annular cells arranged sequentially along the height direction and an arc-shaped cell located at the top center. Specifically, the air cushion buffer trimming deformation layer 4 has two types of cells: low-pressure cells 41 and high-pressure cells 42 (where low and high pressure refer only to the relative pressure within the two cells). Low-pressure cells 41 and high-pressure cells 42 are arranged alternately, with the arc-shaped cell located at the top center being the low-pressure cell 41.

[0036] Under the action of the blast shock wave, the air cushion buffer layer 4 has two energy absorption and buffering modes. First, the cell structure in the normal direction (i.e., the cell structure at the top) will undergo air cushion compression deformation under the action of the shock wave, which can effectively weaken the peak value of the shock wave. As the arc-shaped cell is compressed and deformed, the high-pressure cell 42 nearby can provide short-term support, forming a second steady state of gradient cell structure in the tangential direction; as the shock wave continues to compress the air cushion, the first layer of high-pressure cells can no longer withstand it and the tent collapses further from the top until the second layer of high-pressure cells supports it, forming a third steady state, and so on, forming a multi-steady-state effect.

[0037] As an example, the air cushion buffer clipping deformation layer 4 includes five annular cells arranged sequentially along the height direction and an arc-shaped cell located at the top center; thus, the air cushion buffer clipping deformation layer 4 has three annular high-pressure cells 42 (from top to bottom: the first layer of high-pressure cells, the second layer of high-pressure cells, and the third layer of high-pressure cells), two annular low-pressure cells 41, and one arc-shaped low-pressure cell 41. The air pressure within the high-pressure cells 42 is greater than 15 kPa, and the air pressure within the low-pressure cells 41 is greater than 10 kPa (but less than the air pressure within the high-pressure cells 42). The relative density of the multistable variant structure formed by cell stacking can reach 0.186, exhibiting significant high energy efficiency and lightweight characteristics. Figure 2 As shown, the air cushion buffer trimming deformation layer 4 of this structural form has four steady states.

[0038] As an example, in the air cushion buffer clipping deformation layer 4, the air pressure in each low-pressure cell 41 is the same, and the air pressure in each high-pressure cell 42 is the same.

[0039] As an example, in the air cushion buffer clipping deformation layer 4, the air pressure in each low-pressure cell 41 increases sequentially from top to bottom along the height direction, and the air pressure in each high-pressure cell 42 increases sequentially from top to bottom along the height direction. Thus, among the low-pressure cells 41, the air pressure in the top arc-shaped low-pressure cell 41 is the lowest, and the air pressure in the low-pressure cells 41 below it increases sequentially. Moreover, the air pressure in each high-pressure cell 42 is greater than the air pressure in the two adjacent low-pressure cells 41.

[0040] As an example, two or more air cushion buffer trimming deformation layers 4 can be stacked; wherein the air pressure in each cell of the inner air cushion buffer trimming deformation layer 4 is greater than the air pressure in the corresponding cells of the outer air cushion buffer trimming deformation layer 4.

[0041] Below is a specific example of a bulletproof and blast-resistant tent:

[0042] In this example, the ballistic layer 1 is made of ultra-high molecular weight polyethylene fiber UD fabric, the flame retardant layer 2 is made of high-temperature resistant aramid fiber two-dimensional woven fabric, and the energy-absorbing layer 3 is made of fabric with a density of 50 g / cm³. 3 The tent is made of polyurethane soft foam, with the anti-dent layer 5 made of ultra-high molecular weight polyethylene fiber UD fabric. All the above layers are hemispherical structures, stacked together to form a bulletproof and explosion-proof tent.

[0043] The bulletproof layer 1 is 2mm thick, the flame-retardant layer 2 is 2mm thick, the energy-absorbing layer is 3mm thick, the air cushion buffer and shaping layer 4 has a thickness of 100mm after inflation, and the anti-dent layer 5 has a thickness of 2mm. The overall thickness is greater than 109mm. Tests have shown that this type of bulletproof and blast-resistant tent can protect against 12.7mm 1.1g standard fragments with a velocity of 400m / s, can withstand a 1MPa non-contact shock wave while remaining stable without collapsing, and can extinguish high-temperature explosives in less than 1 second.

[0044] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A multi-stable, flexible, inflatable, bulletproof and explosion-proof tent, characterized in that: The bulletproof and explosion-proof tent has a multi-layer structure, including at least: a bulletproof layer, an energy-absorbing layer, and an air cushion buffering and deformation layer; all of the above layers are made of flexible materials; wherein the bulletproof layer is located on the outermost side, and the air cushion buffering and deformation layer is located on the inner side of the energy-absorbing layer; The air cushion buffer trimming deformation layer is an inflatable structure, including low-pressure cells and high-pressure cells; the high-pressure cells and low-pressure cells are arranged alternately along the height direction to form an air cushion buffer trimming deformation layer with a multi-stable structure.

2. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in claim 1, characterized in that: The arc-shaped cell at the top is the low-pressure cell.

3. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in claim 1, characterized in that: In the air cushion buffer clipping deformation layer, the air pressure in each low-pressure cell increases sequentially from top to bottom along the height direction, and the air pressure in each high-pressure cell increases sequentially from top to bottom along the height direction; and the air pressure in each high-pressure cell is greater than the air pressure in the two adjacent low-pressure cells.

4. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in claim 1, characterized in that: Two or more air cushion buffer trimming deformation layers are stacked; wherein the air pressure in each cell of the inner air cushion buffer trimming deformation layer is greater than the air pressure in the corresponding cells of the outer air cushion buffer trimming deformation layer.

5. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in claim 1, characterized in that: The air pressure in the high-pressure cell is greater than 15 kPa; the air pressure in the low-pressure cell is greater than 10 kPa.

6. The multistable flexible inflatable bulletproof and blast-resistant tent as described in any one of claims 1-5, characterized in that: The innermost layer of the bulletproof and explosion-proof tent tarpaulin is an anti-dent layer.

7. The multistable flexible inflatable bulletproof and blast-resistant tent as described in any one of claims 1-5, characterized in that: A flame-retardant layer is provided on the outside of the energy-absorbing layer.

8. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in any one of claims 1-5, characterized in that: The ballistic layer is a fiber ballistic layer; the energy-absorbing layer is made of porous polyurethane foam; and the air-cushion buffer and clipping deformation layer's inflatable membrane is made of polyurethane superelastic material.

9. The multi-stable flexible inflatable bulletproof and blast-resistant tent as described in claim 7, characterized in that: The flame-retardant layer is made of high-temperature resistant aramid fiber.

10. The multistable flexible inflatable bulletproof and blast-resistant tent as described in any one of claims 1-5, characterized in that: Each layer of the tarpaulin has a hemispherical structure, and the air cushion buffering and shaping layer includes five annular cells arranged sequentially along the height direction and an arc-shaped cell located at the top center.

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